Pressure measuring transducers of the field of the invention have a ceramic pressure measuring cell in a housing, wherein the pressure measuring cell is arranged in a measuring cell chamber in the housing, wherein the measuring cell chamber has an opening, through which the pressure measuring cell is contactable with a media pressure, wherein the housing has a radially inwardly extending, annular shoulder, which the housing opening surrounds, and which forms, for a sealing ring, an axial abutment surface, on which the sealing ring lies, against which the pressure measuring cell is axially clamped with a tightening apparatus. For positioning the pressure measuring cell and the sealing ring in the housing, rings of angular cross section are applied, which are inserted in an annular gap between the lateral surface of the pressure measuring cell and the housing wall, and which grip around the edge of the opening-side end face of the pressure measuring cell.
A pressure measuring transducer of the field of the invention is disclosed, for example, in the European Patent EP 0 594 808 B1, wherein the there described ring of angular cross section serves especially to enable a modular construction of the housing, in the case of which the axial shoulder is embodied on a process connection element, which has the housing opening, through which the pressure measuring cell is to be supplied with a pressure, wherein the connection element has on its lateral surface a screw thread, which engages in a complementary internal thread in the housing, wherein the internal thread is arranged in a frontal end section of the sensor chamber. The task of the ring of angular cross section in this connection is divided into two parts, namely, on the one hand, the axial and radial positioning of the pressure measuring cell in the housing and, on the other hand, the holding of the O-ring before the mounting of the connection element. Especially, the stress behavior of the pressure measuring cell in the housing assumes, however, a sufficiently elastic material for the ring of angular cross section, which, as regards the radial support of the sealing ring by the ring of angular cross section, requires compromises, since the sealing ring and ring of angular cross section have materials of similar hardness, and, thus, the ring of angular cross section scarcely appears suitable for support of the sealing ring under pressure loading.
In the case of smaller pressure measurement cells, it is, however, necessary that the position of the sealing ring be exactly defined, since the relative importance of a radial shifting of the sealing ring increases with decreasing diameter of the pressure measuring cell.